Forty years ago next month, 50 million Americans tuned in to watch a prime-time, televised spectacle: a tennis match promoted as the Battle of the Sexes. Fifty-five-year-old Bobby Riggs, a former Wimbledon and U.S. singles champion, as well as a self-described male chauvinist pig, challenged the reigning women's champion, 29-year-old Billie Jean King. Amid wild hype and theatrics, they played at the Houston Astrodome. And Billie Jean King crushed Bobby Riggs in straight sets: 6-4, 6-3, 6-3.

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UNIDENTIFIED MAN: Excitement engendered all over the country as Billie Jean hugs her husband Larry King. It began to become a cause celebre, equality for women.

BLOCK: But was it all a sham? Did Bobby Riggs intentionally throw the match for a big payday? That rumor has swirled for years. And now, it's bolstered by an ESPN investigation, which finds new evidence that Riggs threw the match. And it makes this claim that he did so to cover his gambling debts to the Mafia.

BLOCK: Let's talk first about the hoopla that surrounded this match, Riggs versus King, right? Riggs, a loudmouth, showboat, hustler, and then Billie Jean King, a champion for women's rights. Describe the scene as they were brought into the Astrodome in Houston.

JR.: They're carried in. Billie Jean King is carried in looking like Cleopatra by muscled men. Bobby Riggs was carried in, and his bosom bodies, young women were surrounding him as they were brought into the Astrodome.

BLOCK: Why were there rumors over the years that this match was, in fact, thrown?

JR.: I think the tennis people were just astonished at how Bobby Riggs didn't look like the Bobby Riggs that they knew. And that they had seen just four months earlier when he defeated Margaret Court, who was the number one ranked player in the world. Four months after that, he just looked nothing like that. He had a great service game, and yet he missed his first serves nearly half the time, and some of his return shot barely made it to the net.

BLOCK: OK. Well, let's talk about these new allegations. You talked to a man named Hal Shaw, and he described hearing a late-night conversation 40 years ago before the match. What did he tell you?

JR.: Well, Hal Shaw was in the pro shop at the Palma Ceia Golf Club in Tampa, Florida, and he heard voices and looked through a window of a door, and he saw Frank Ragano, who was a member of Palma Ceia and a mob attorney, come in first, followed by two of the most infamous mob leaders of the 20th century whom Shaw says he recognized from their newspaper photographs. The first was Santo Trafficante Jr., who led the Florida mob. The second man was Carlos Marcello, who was the leader of the mob in New Orleans.

And there was a fourth man there who Shaw didn't recognize. They sat down, and Shaw says he was astonished to hear them talking about Bobby Riggs. Ragano tells the men that Riggs has brought them a proposal that he's going to play two exhibition matches against the top women players of the time - Margaret Court and Billie Jean King. Ragano says Riggs is going to beat Margaret Court, but then purposefully lose the match against Billie Jean King. Ragano mentions Riggs owed them more than $100,000 in gambling debts.

And they - after about an hour of discussion, they agree in principle to go forward with this plan, and Shaw hears every word of it and repeats it to us for this story.

BLOCK: He's telling you he heard this through a closed door, right? And he was 20 feet away. Was there any doubt in your mind that he could have heard what he claims to have heard?

JR.: Well, I spent a lot of time with Hal Shaw before we decided to do this story, Melissa, and I had known him previously with work I had done on a book about Babe Didrikson. So I knew him to have a great memory. And every single time I've asked him over a number of months, he's told the story the same way with the same details.

BLOCK: Why would Hal Shaw come forward with this for the first time 40 years after it happened?

JR.: Because he feared retribution from the mob. For decades, there were mob killings, gangland killings, and he was worried if he had said anything prior to this that it would get out and his life would be on the line.

BLOCK: And he doesn't worry about that now?

JR.: He says he doesn't. He felt strongly that he wanted to, as he put it, set the record straight and let the world know that the match that they watched on that September evening in 1973 was not what it was purported to be.

BLOCK: Well, apart from Hal Shaw telling you this, is there anybody else who backs up his version of events?

JR.: This was really just where I started. I kept finding out more and more things that corroborated what Hal Shaw said. For instance, Larry Riggs, who was Bobby Riggs' son, says that yes, in fact, his father did know quite a few mafia leaders. One of the more interesting things that Larry Riggs says is there was a mobster named Jackie The Lackey Cerone, who was number two in the mob in the '70s in Chicago, who his dad played golf with and played cards with.

And that Jackie Cerone actually had men of his who Larry Riggs recognized come out to California where Bobby Riggs was preparing for the Battle of the Sexes and meet with Bobby Riggs several times in the weeks leading up to the match with Billie Jean King.

BLOCK: OK. Well, you put this allegation to Billie Jean King, this claim that Bobby Riggs intentionally threw the match against her or tanked. Let's listen to some of what Billie Jean King told you in response.

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BILLIE JEAN KING: There is no question I have played matches where players have tanked, and I know what it feels like, and I know what it looks like, and he did not.

BLOCK: You know, Don, I was 11 years old when this match was played, and I remember distinctly, even at that age, thinking this was a big moment, something happened here. And I feel like this is a say it ain't so kind of feeling right now that maybe this wasn't what it appeared to be.

JR.: Well, I've had that feeling throughout the reporting of this piece since the late spring when I began. I watched it as well. I was 9 years old and was really swept up and all the hoopla leading up to it. But at every turn in this reporting, I found out things that seemed more convincing that this was not on the level. Bobby Riggs, for instance, did not practice at all in the four months prior to playing Billie Jean King, which was not like him. His son, Larry Riggs, was so upset about it that he actually bet on Billie Jean King to beat his father.

And he just was partying in Beverly Hills. He gained 15 pounds. And Gardnar Mulloy, a great tennis legend who's 99 years old, told me that he was absolutely convinced Bobby threw it. Bobby hung around with mobsters. And as Mulloy puts it, Bobby Riggs didn't really even have to throw it. He didn't put himself in position to physically win.

BLOCK: But Billie Jean King there saying I won this fair and square. Bobby Riggs up until the end said got to hand it to her. She played a great match.

JR.: Right. But, you know, in our interview, Billie Jean was surprised to hear that Bobby had these mob connections. At one point, she was saying that's not Bobby. He didn't know mobsters when, in fact, he did. He knew quite a few of them. But what I was really struck by, too, in the reporting, Melissa, is how many people in the tennis world have just assumed this for 40 years.

When I went to Wimbledon this summer and talked to some of the old guard of tennis, many people that I spoke with sort of just said, well, we just always assumed he threw it because of the way he played, how he didn't prepare and also because of who Bobby Riggs was.

BLOCK: That's Don Van Natta. His piece for ESPN is titled "The Matchmaker: Bobby Riggs, The Mafia and The Battle of the Sexes." Don, thanks so much.

CHRISTOPHER BYERS: Thank you. Melissa.

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